We report on experiments to investigate the evolution of stresses under constant heating-rate conditions in Nb/Al multilayer films that react to form the trialuminide, NbAl3. The stress-thickness values during thermal cycling were determined by measuring changes in wafer curvature. The multilayer films were deposited onto thermally oxidized silicon wafers, and two bilayer thickness values of 23.2 and 72 MI were studied. The curvature data indicated that the formation of NbAl3 was accompanied by two separated tensile transitions. These transitions were attributed to the reduction in volume that occurs upon the formation of the trialuminide. The curvature studies were compared with differential scanning calorimetry investigations of the reaction conducted under similar conditions. It was found that the temperatures for the tensile transitions were comparable to those for the maxima in the rate of heat evolution in the calorimetric studies.